IEEE802.11 provides a cost-effective solution for networking terminal apparatus including for example computers by wireless. With new developments in signal processing and modulation technologies, the standard has been enhanced to support physical layers with higher data rates in the present wireless transmission apparatus used in wireless LAN (see, for example, Non-Patent Document 1 and Non-Patent Document 2).    Non-Patent Document 1: “Local and Metropolitan Area Networks—Specific Requirement—Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications: Higher-Speed Physical Layer Extension in the 2.4 GHz Band”, IEEE Standard 802.11b-1999, IEEE, September 1999.    Non-Patent Document 2: “Local and Metropolitan Area Networks—Specific Requirement—Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications: Higher-Speed Physical Layer Extension in the 5 GHz Band”, IEEE Standard 802.11a-1999, IEEE, September 1999.